


Who did you kill

by squire



Series: Form, Truth, and Regret [2]
Category: Mononoke, Sherlock (TV)
Genre: Alternative Scenario, Angst, BBC canon non-compliant, Gen, The one where Sherlock is a demon hunter, Unresolved Romantic Tension, arc Noppera Bou, dream-like reality, episode His Last Vow
Language: English
Status: Completed
Published: 2014-03-05
Updated: 2014-03-08
Packaged: 2018-01-14 15:31:09
Rating: Not Rated
Warnings: No Archive Warnings Apply
Chapters: 4
Words: 6,101
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1271792
Author URL: https://archiveofourown.org/users/squire/pseuds/squire
Summary: <blockquote class="userstuff">
              <p>Sherlock crossover with the Noppera Bou arc of the anime Mononoke.</p><p>John Watson is killed. <br/>Mary confessed to having killed him.<br/>Sherlock faces his greatest adversary in his search for the truth. </p><p> </p><p>
  <i>“One visit. That’s all I ask.” Then he cast a sidelong glance at the grey-haired policeman and allowed sincerity to show up on his face: “And I won’t harm her, in case you’re worried.” </i>
</p><p><i>“Jesus, Sherlock.” Lestrade wasn’t sure if allowing Sherlock one session in the interrogation room with the woman guilty of murder of John Watson was the worst idea – or the best. “For my part, I wouldn’t be overly cross with you if you did. But...” he waved his hand all around them, words becoming superfluous.</i><br/> </p><p>A/N: The traditional birthday gift fic for my readers. Yes, another year in this fandom passed by. Enjoy!</p>
            </blockquote>





	1. Part one

**Author's Note:**

> I strongly recommend to read my previous work in this 'verse, "What you fear the most", first. The mythology behind this world is explained there more in detail. For those who won't, I'll summarize shortly: Sherlock is a demon hunter (and a detective, of course) who hunts demons associated with strong human emotions (and thus often responsible for crimes). His own nature is somewhat of a mystery - definitely not human. The closest he could be describe is a fox demon. He has pointed ears and canines, carries a special sword that can be unsheathed only when the Demon's true nature is known, and otherwise is just the good old sociopath as we know him.
> 
> Also, I mention his Sword of Exorcism a lot, so here you have a picture of what it truly looks like. http://www.youtube.com/watch?v=WTQ6UOLaQek

**Notes for the Chapter:**

> My sins against the English language in this chapter were kindly alleviated by the amazing ArianeDeVere.

_Captain John H. Watson, MD, formerly of the Fifth Northumberland Fusiliers, was murdered._

_The culprit was the victim’s newlywed wife, Mary. For her crime, she was incarcerated immediately._

 

The words felt like a fiction despite the bland reality of the police report file paper they were printed on. Sherlock ran his fingers along the signature at the very end of the statements page: perfectly neat and legible, hand still unused to the new surname but sure in its delivery; the pen didn’t shake. 

 _I accept responsibility for my crime_ , she had said and signed the statement. They haven’t heard another word from her since. 

Lestrade kept shaking his head as they passed through the NSY corridors. 

“There’s nothing to do, Sherlock. The case is solved. She confessed, for God’s sake.” 

“One visit. That’s all I ask.” Then he cast a sidelong glance at the grey-haired policeman and allowed sincerity to show up on his face: “And I won’t harm her, in case you’re worried.” 

“Jesus, Sherlock.” Lestrade wasn’t sure if allowing Sherlock one session in the interrogation room with the woman guilty of murder of John Watson was the worst idea – or the best. “For my part, I wouldn’t be overly cross with you if you did. But...” he waved his hand all around them, words becoming superfluous.

 

The door closed behind him with a sharp metallic _click_ of the lock. The blonde woman seated at the table did not raise her eyes. Sherlock took a seat opposite her and for a very long while, he just stared. 

“Just _what_ did you do?” he asked after minutes of silence. 

“What do you think you’re doing here?” she countered. “I haven’t asked for you. I wouldn’t, even. Your deductions won’t be of any help here.” She emphasized the word with bitterness. 

Sherlock put his elbows on the table and steepled his fingers under his chin. “In contrast with what I usually say, personally, the belief that the facts and clues alone can lead to solution of a crime does not sit well with me. Without seeing and understanding the person behind the crime, the real solution is unattainable.” 

Mary looked – tired. Exhausted to the point of breaking. “But you already know what happened. Leave me alone.” 

“Oh, everybody seems to know what happened.” Sherlock smiled, his fake smile that showed just the tips of his canine teeth. “From the Chief Superintendent down to the last Constable, they all think they know what happened. Mary Watson, the devil who killed her husband and the father of her unborn child, only a month after their wedding.”  

He continued, his voice devoid of any horror or compassion, instead laced with something dangerously close to sick delight: “Such a heinous crime. Shooting him in his sleep.” 

Mary blinked several times and frowned: “That’s not what happened.” 

“Oh, it isn’t?” Sherlock retorted, unfazed. “Oh yes, you’ve poisoned him, of course. Something in his tea. What a cruel irony of fate.” 

“That’s wrong, as well.” Mary evaded his eyes, and there was a hint of distress in her voice.

 Sherlock measured his words like the contents of his potions: “Then how did it happen?” 

Mary drew in a deep breath and then she flinched as if she heard a sharp sound. Sherlock watched her, his fox-like eyes alight. 

“Is something the matter?” 

“Oh. Nothing.” She rubbed her hands together. “I’ve... I’ve forgotten.” 

Sherlock’s smile grew broader. “It doesn’t really matter, does it? I happen to think you didn’t do it – not without aid. There were no witnesses and no evidence, just your own admission of guilt. I do not believe you acted alone.” 

He leaned forward: “I think that it was the work of a demon.” 

“Demon?” she laughed disbelievingly. 

“You’re sure you’re not acquainted with them? What about your past? I believe you carry an awful lot of them, in fact.” 

“That’s nonsense.” Her mouth was a thin, firm line. “I did it for reasons that are my own and none of your business. I’ll pay for it and that’s the end of it.” She looked towards the mirror glass on the far wall, as if she wanted to plead with the unseen officer behind it to come and send Sherlock away. 

“Oh no, Mary. You know, people always have a certain air about them. You don’t strike me as a woman ready to go to prison tomorrow.” 

If there was anyone overseeing them through the one-way mirror, they didn’t react. She looked at Sherlock defiantly. “And yet, that’s exactly what will happen. Why is it of any bother to you?” 

Through the corridors, from behind the locked door, faint sounds reached them. Sounds of commotion somewhere in the upper storeys, voices raised in alarm. Mary cocked her head to listen. Sherlock paid it no heed. 

“You know... you seem different. To the normal Mary.” 

She laughed again, momentarily distracted: “You have no idea about how I act under normal circumstances. You have no idea who I really am, do you? All you’ve ever seen of me was an act.” 

 _Liar_ , Sherlock remembered his deduction from the night they met for the first time. One deduction that rendered all the others empty. 

Thin wisps of smoke crept through the crack under the door of the interrogation room. Mary noticed it and her eyes widened. 

“But you can trust me. I can help.” Sherlock insisted. 

Mary’s answer was intercepted by a sound of something heavy falling to the ground outside their door. Then, a voice called out, strangely muffled.

“Where are you? Get out of there!” 

Sherlock spun around, pointed ears quivering. “Impossible,” he murmured. He quickly turned to Mary: “Whatever happens, stay. Don’t leave. You mustn’t leave.” 

Mary rose from her chair. “You gone crazy? If there’s fire, we must leave! Somebody is coming for us already...” 

Sherlock pinned her down to the chair, not minding her struggling. “Let me go!” she screamed. “Why are you getting in my way? This is madness! We’re gonna die–” 

“You are safe as long as you stay in here,” Sherlock hissed. The lock to the interrogation room cracked open. 

Sherlock jumped to it, fingers curling around the sheath of that strange little sword of his. A figure of a man with a gas mask on his face stood in the door. The corridor was full of suffocating smoke. 

“My, my.” The intruder closed the door just as Mary started to feel tears prickle in her eyes. 

“Don’t worry, sweetheart. I’ve come for you. You’re not one to rot in prison.” 

Mary, as if she was under a spell, took few steps towards the intruder. 

“So I was right,” Sherlock gritted through his teeth, “she had an accomplice. She was possessed. Though I must admit, you revealed your Form earlier than I thought.” 

“Oh, you think so?” The man pulled off his mask. “Well, witness my Form.”

 

It was Moriarty, eyes dancing with that insane spark that’s always been there, with far too many teeth in his grin. The sword in Sherlock’s hand rattled its teeth in vain. Sherlock looked at it with genuine surprise. 

“This is not your true Form. Moriarty’s dead. He blew his brains out. He’s dead.” 

“There is something about being dead, Sherlock,” Moriarty mused, “oh, look to whom I’m talking. But you’re gonna love it this time. No one ever bothers you.” 

Moriarty tossed a gun at Mary. She caught it with a practiced ease, checked it, flipped the safety off and aimed at Sherlock. 

“Get out of my way.” Her voice was small but there was an edge to it which spoke less of pleading and more of a threat. 

“Don’t leave, Mary.” Sherlock repeated. “If you believe this place holds you, it is a prison. If you don’t wish to leave, it will become a fortress. Let me help.” 

Her voice was frail but her posture was not. “Sherlock, I swear... you can’t help me. One more step and I _will_ kill you.” 

“Do you really want to run away – forever?” From the wince on her face he could tell her resolve was wavering. She reminded him of a cornered animal, ready to bite. 

“Sherlock, darling.” Moriarty drawled. “You heard what she said. Infinite providence lies with me, you see? I can take care of her.”

 

Sherlock took one step forward.

 

Mary pulled the trigger.

 

Dark red rose bud bloomed on the front of Sherlock’s crisp white shirt. When he looked back at her, somehow it felt as if a mask fell off his face, the one he used to wear in the company of humans. She used to read him as a book but suddenly she couldn’t read a single trace in his features. 

As Sherlock fell to the ground, the mocking voice of Moriarty flowed through the clouds of smoke: “Wander now, in search of you precious Form.”

 

 

***

 

The next thing Mary registered, the first thing that truly came to her through the fog of smoke and confusion, was that they were in a sheltered place somewhere, resting. 

“We should be safe for now.”   

She allowed herself to relax minutely and then, for the first time since their escape, looked her abductor squarely in the eyes. 

“So....” she began, “.... you.” She didn’t really know where to begin. Moriarty sighed. 

“All those ridiculous rumours. But well, if it helps, think that I am a demon.” 

She looked at him sharply. “You’re not.” 

He grinned. “Then I’m not. Does it matter? You’re free. We’re alive. Bridges burned.” 

She clenched her hands and then she touched her face, rubbing her fingers along her jawline. When she looks at her fingertips, she was almost surprised that they were clean, as if she expected to find dried blood under her fingernails. 

“The past is not a problem any more,” Moriarty assured her.

 

 _The problems of your past are your business_ , John would have said to her. Oh, if only he knew how her problems would catch up with her, and how soon. 

 _It’s all I need to know_ , he would have said when he would decide never to want to know. So forgiving. So accepting. So good.

 

Too good for his own good.

 

 

**Notes for the Chapter:**

> For those who like to hunt for references: Sherlock prompting different scenarios of John's death, the smoke, and the mask on the face of the abductor, they are direct references to the anime.
> 
> I'm sure my readers know their Sherlock enough to spot the Sherlock references on their own.


	2. Part two

**Notes for the Chapter:**

> I strayed substantially from the actual plot of the anime arc in this part, mainly because the Masked Man here actually proposes a marriage to the abducted woman and I seriously didn't see Moriarty as the marrying type. 
> 
> Also, Mary's backstory somehow became darker than I planned. 
> 
> Sincere apologies to for my use of the name Amy - but seriously, you can't cast a woman named Amanda Abbington in the role of a character with the initials of A.G.R.A. and don't expect the fandom jumping to conclusions.

_There were those words, overheard some time during their engagement party, hanging at the back of her consciousness ever since. The words of John’s old pal, Bill Murray, as she heard him talk to John with that disarming, inebriated sincerity:_   
  
_“Look at you, Johnny, all about to settle down. If that mad bastard of a friend of yours hadn’t dashed off two years ago, I bet you wouldn’t even notice her.”_   
  
_Sometimes, Mary wondered._   
  
_But Sherlock did leave, and John did notice her, and he did accept her into his life. It was all so easy._   
  
_“Well, I bet she’s better shag than him at least,” Murray hiccupped with laughter over his poor joke. John never stopped smiling, but she could see the tightening of his mouth from the other side of the room, and she watched him fishing out his phone and calling a taxi for Bill to take him home._   
  
_Deep inside, she knew she couldn’t replace Sherlock. Most of the time, she didn’t have to. And if she sometimes cried, if she let silent tears fall into the sink in the locked bathroom; it was because she wanted to._   
  
_It was so easy to set the trap. It took all her strength to stay trapped._

 

***

  
“What now?”  
  
They were hiding in a small flat somewhere in Chelsea. The owners were on holiday, the neighbours barely looked at them when they met them walking down the corridor of the nondescript building. The anonymity of modern life.   
  
“We won’t be found.”  
  
“Won’t we?” She checked the blinds on the windows. “After that stunt you’ve pulled down there...”  
  
“You’re an American, darling. Don’t tell me you don’t enjoy a bit of a drama.”  
  
“You could go straight for having your face broadcasted on every screen in the country, the effect would be the same,” she remarked, eliciting a manic grin on the face of her companion.  
  
“You’re really getting the hang of it,” he winked at her.  
  
“Well, dramatic entrance done. What about some quiet leaving? Spared any thought on that?”  
  
Instead of any direct reply, Moriarty wandered the flat a while, humming to himself.  
  
“Mary, Mary, quite contrary...” Somehow, it grated on her nerves more than she would expect.  
  
“...and pretty maids all in the row!” Moriarty finished aloud, turning to her abruptly.  
  
“It’s all set, love. I said I could take care of you – well, don’t expect me to be the boring husband you’ve tied yourself to like the good little wife you never were. There are things to do, places to see – people to kill – oh I think you won’t be disappointed.”  
  
“You want to recruit me?”  
  
His smile was reassuring, a strange counterpoint to the cold gleam in his eyes. “What else would you want to do? You blew up your mission of the last two years, and quite spectacularly so, I must say. There’s no coming back now, Amy.”  
  
She flinched as if he slapped her. “I’ll stick with Mary, thank you.”  
  
Moriarty threw up his arms as if begging heaven to crash over such stupid sentimentality. “This is the first day of your new life!”  
  
“I’ve been there already.” She touched her wedding band. “Didn’t last long.”  
  
“Are you deliberately blind to me offering you a reason for living, honey?”  
  
“How do I know I can trust you? I should hate you.” Something felt very wrong as she realised she was fishing for reasons to resent him. “You strapped John to a bomb once,” she added.  
  
“Such are the bedtime stories in the Watson family?” Moriarty rolled his eyes. “Okay, I did that. Business. Pure business. Nothing personal against John Watson. I don’t let sentiments interfere with my job,  _Mary_.”  
  
“You sound just like him,” she made a face.  
  
“Like dear old Sherlock? Of course, you know what they say. Two sides of the same coin. Good of you to mention him, actually. If I ever laid a finger on your precious  _late_  husband, it was solely to have one up on Sherlock.”  
  
Now the hate came naturally. She felt rage, fueled by guilt, swelling up her throat. “That’s why anything ever happened to him, isn’t it? Everyone used him just to get to Sherlock. Was he ever anything more than a mean to an end?”  
  
“You tell me,” he drawled, obviously amused by the unfairness of her accusation.   
  
She hated that he had a point. He once used Semtex and laser points. She used home-baked bread and kisses. She was never anything but a little fraud of a wife, and if she actually wanted to be more, nobody cared.  
  
The building tension was interrupted by a sharp sound – Moriarty’s phone pinged with an incoming text message. As he read it, something dark settled on his face, something Mary couldn’t decipher. He made to hide the phone back in his pocket but she was quicker.  
  
“I believe that’s for me.”  
  
He scowled and shoved the phone in her face.  
  
–If your new pet got her breath back, tell her to call me. We may need a word or two. CAM  
  
Mary wanted to hurl the phone across the room but, in the end, settled for deleting the message with vicious meticulousness.  
  
Moriarty was curt. “When Magnussen contacts you again, you may tell him to piss off.”  
  
She wrapped her arms around herself. “He’s got nothing on me.” With eyes tightly shut, she added, in a quieter tone: “Not anymore.”

 

***

  
Moriarty didn’t show her any more messages from Magnussen even when she knew they were still coming. Magnussen always timed his reminders well. She remembered the telegram, read aloud in front of the whole wedding party, like a gauntlet thrown in her face:  
  
Mary – lots of love, poppet. Oodles of love and heaps of good wishes from CAM. Wish your family could have seen this.   
  
Spoiling the day that should have been the happiest in her life.  
  
It was the happiest day in the life of Mary Watson, at least.

 

***

  
They were in the kitchen, when she heard the sound of the balcony door opening, back in the living room. The  _thud_ of the door closing was carefree, whoever found them, they weren’t even trying to sneak on them.  
  
When Mary entered the living room, she found Sherlock lounging comfortably on the sofa as if the flat belonged to him. He began clapping his hands together in mock applause.  
  
“Congratulations. That was quite a wonderful play. I enjoyed it very much.”  
  
Moriarty snarled: “Honestly, your manners. Haven’t they taught you that, once murdered, you should bloody stay dead?”  
  
Mary found it difficult to find any words, and when she did, the result was lame: “That’s not possible. It was a kill shot.”  
  
“Sorry to shatter your belief on how good a shot you are.” His voice was dripping with sarcasm. Then he turned on Moriarty.  
  
“Life. Death. Does it matter? You can feel the difference, but you don’t have to fear the change. You see – pain...” He touched the blood stain on his shirt.  
  
“... loss...” The corners of his mouth curled up in the reverse image of the scowl on Moriarty’s face.  
  
“...heartbreak...” He turned his gaze to Mary pointedly... “It’s all good.”  
  
He sighed the way he always did when he had to explain the obvious. “If I accept my state, it is quite easy to make it work.”  
  
Then he stood up and brought his sword forth once more. “I see you’ve become really cosy in this Form, demon. But where’s your real face?”  
  
Moriarty’s skin began to darken, his hair grew longer and turned white. His features began to resemble a fox, even more than Sherlock’s did.  
  
“Two sides of the same coin,” Sherlock murmured.  
  
“I can’t be  _you_ ,” Moriarty hissed. Sherlock produced a small mirror from his pocket. When he threw it in the air, it expanded tenfold, hiding him from Moriarty like a shield. In the reflexive surface, all Moriarty could see was his own appearance. With a terrible cry, he fell to the ground.  
  
The floor shattered, multiple cracks ran along the walls of the flat. Mary looked around in dismay. Sherlock came over to her, his voice unexpectedly gentle.  
  
“It was all a fake.”  
  
She fell to her knees to Moriarty’s side, feeling for his pulse. An automatic move of a well trained nurse – never before so pointless. “Why? Why would he do it?”  
  
“Why would  _you_  do it? Wanting Moriarty to save you – to offer you a new life? Nobody can do that, Mary, except for yourself.”  
  
“But why this play? Why would  _I_  want him to abduct me?”  
  
Sherlock looked pensive. “The demon must be hiding something. Something he needed you not to notice.”  
  
The thought of Magnussen’s text messages flashed through Mary’s mind. She bit on her tongue, not letting out a word.  
  
Moriarty, as if sensing the loyalty in his new ally, sat up and, collectedly as he could, smoothed his hair. It was black again, stark against his pale skin, as usual. “I’m afraid I won’t bend to your will.”  
  
Sherlock merely raised his sword. “If you will not show me your true Form, then at least be quiet for a while.”  
  
Magic filled the air and the Moriarty in the room vanished. Only his reflection in the concave surface of the mirror shield remained, distorted and raging, but silent.  
  
Sherlock: “Well then. Shall we restart our little play?”

**Notes for the Chapter:**

> Mononoke references in this chapter (for the hunters): "This is the first day of our new life", Sherlock accepting his dead state, Moriarty looking like Sherlock's demon counterpart.


	3. Part three

_The intertwined fates of men give the demon its Form._  
  
 _When a being not of this plane clings onto a person’s thoughts and feelings, it creates a demon. Truth is a demon’s physical state, and Regret is a state of mind._  
  
  
“So you’ve come to kill my demon?”  
  
“If I could kill it now, my work would be easy. I must discover the demon’s Truth and Regret, and without its Form, I cannot draw the Sword of Exorcism. Your demon is s a troublesome one, indeed.”  
  
Sherlock’s magic created a changeable space around them, one that resembled a stage; ready for a story to unfold. With a gesture full of theatrical flourish which distinguished his Exorcist form so sharply from his more contained, everyday human conduct, he opened the first act.  
  
“The life of Mary Watson, part the First.”  
  
 _He’s taken on cycling to work every morning._  
  
Mary looked out of the kitchen window, watching her husband rounding the corner, and clenched her hands on the worktop. Past the thirty-five wasn’t the best age for a first baby, and though the bicornuate uterus diagnosis that showed up after her first screening wasn’t a horrible problem in itself, it just added to her decision to take a sick leave for the better part of the pregnancy.  
  
They didn’t have bars over their ground floor windows; this was a safe neighborhood. It just felt as if they had them.  
  
 _Every day_ ,  _he’s finding new little ways of escaping_ , she thought. The cycling was just a tip of the iceberg. Meeting his old Uni mates for a game of cards every Friday, bets rising just a little every time. John’s always been a gambler. Soon will come the day when he would ask to be taken along on a case again. Some day after that, he won’t even have to ask.  
  
And just like that, with the constant lure of danger on the edges of John Watson’s new life, this new life would be soon forsaken. It would be over.  
  
Her trap would slowly rot from inside and leave her free.  
  
Except she knew that, with the child on the way, the equation has changed. This easy way out has closed in front of her. Because even when she knew the exact extent of John’s conscious determination to love his wife, she also knew how he would love his child: to the last draw of his breath, to the last drop of his blood, with all his broken heart, mindless of the pain.  
  
He would always come back to her, no matter what, because of the child.  
  
Her trap was never more secure.  
  
“Why did you not leave him?” Sherlock was standing behind her, leaning casually against the kitchen table. His eyes, attentive as ever, scanned the contents of their perfect little household.  
“Who is it that you really killed?”  
  
He startled her. “Who did I really kill?” She refused the question making any sense to her. She felt the wooden handle of a kitchen knife beneath her fingers, a familiar shape and weight after months of cooked dinners. The blank walls of the Yard’s interrogation room closed on her once more.  
  
“Mary,” Sherlock was standing in front of the one-way mirror, “if you believe this place binds you, it will be your prison. It’s the same as your house. You thought of it as a prison.”  
  
She frowned on her own reflection as if she saw herself for the very first time. “Why did I not simply leave?” Oh, but she knew an answer to that.  
  
The scenery changed once again.  
  
The dimply lit room was furnished with expensive taste and meticulous attention to details; every piece served a purpose. A Spartan room, functional and effective: Magnussen’s office.  
  
There were two people in that room with them: Charles Augustus Magnussen himself, and Mary. Only it wasn’t Mary for that moment: there was still a lingering undertone of Amy. Her hair was already blonde, but still long, and Magnussen was  _twirling_  one of the strands around his forefinger as he spoke to her, ignoring her personal space with the same malicious delight with which he always disregarded every social norm.  
  
“You’re so... exceptionally talented. It’s almost a shame to waste such skills, but there you have it: Man proposes...”  
  
He abandoned her hair in favour of taking one of her hands and bringing the inside of her wrist to his nose.  
  
“You should wear this.” He produced a small bottle of perfume out of his pocket. “You’re not that old for a bit of juvenility.”  
  
“My perfume is just fine for me, thank you.” She didn’t sound like thanking at all.  
  
“This is my favourite,” he insisted and rubbed a drop into the smooth skin just above her veins. “Mmmm... delectable,” he hummed and then he licked her skin, a broad swipe of his tongue. “You’ll learn to like it too; it’s just the perfect scent for you.”  
  
Mary watched as her former self did her best not to lash out and strike that lecherous face, her small frame stiff with suppressed rage. “What if Watson simply won’t be interested?”  
  
“Then make him,” Magnussen smiled, his expression designed to silence any arguments.  
  
“But I don’t worry,” he continued. “You’re so good. He’ll be eating out of the palm of your hand by the end of this year. You’ll make yourself indispensable to him.”  
  
Sherlock looked at the scene with avid interest. “Oh, this  _is_  a puzzle.”  
  
“Is it?” Mary looked on with sour distaste showing on her face. “It’s a plain blackmail, nothing more. Magnussen knew things about my past. He had information about all my hits. He threatened me that he would alert the CIA and the families of my victims if I...”  
  
“If you didn’t marry John Watson,” Sherlock finished for her. “Your entire acquaintance, engagement, marriage – it was an assignment? Why would he use you in such manner?”  
  
The threatened woman must have asked the same question because Magnussen was speaking again. This time, he looked past her, his dead-stare settled in the direction of their dreamy visitors as if he could see them.  
  
“Every person has their pressure point. There’s a man – a man in hiding, but he won’t stay there for long – whom I’d very much like to own. His pressure point is no other than his former flat-mate; you’ll become the flat-mate’s pressure point and thus, my dear, you’ll give me the leverage I need on Sherlock Holmes.”  
  
Mary turned her back on the scene. She found herself facing a mirror – she remembered it from her previous visit, but the addition the trapped demon – of Moriarty’s figure banging his fist from the other side of the glass – was definitely new. He seemed to mouth a word on her, urgent in its repetition, his eyes commanding what his voice could not:  _DON’T. DON’T SHOW HIM THAT._  
  
She collected her resolve. “That’s all. He set the terms, I agreed. There’s no need to replay this.”  
  
Sherlock gave her an unreadable stare, but in the end, he simply nodded. “Let’s move on, then. The life of Mary Watson, part the Second.”

 

***

  
The sight of the familiar wallpaper of their suburban living room grounded her a bit. She looked around for some signs of their relative position in time: Sherlock seemed determined to take the scenic route.  
  
Oh yes. There was Moriarty staring at her silently from the mirror hanging above the mantelpiece.  
  
“Silence really does suit him, doesn’t it?” Sherlock smirked at her as he flopped himself on the sofa. “Trust me, even as dead, he tends to prattle far too much.”  
  
“Is this home?” Mary’s voice shook just a little. “I mean – are we visible?”  
  
“Does it matter? Why are you so nervous?”  
  
“I’m not,” said she, too quickly. “It’s just... John would be home any moment. This is the time he usually comes back from work...”  
  
Sherlock stared at the ceiling. “Let him, then.”  
  
“Are you serious?” She struggled to keep her voice in check and pointed at the mirror. “With... him there? And you – you  _never_  come over, doesn’t matter how many times  _he_  invited you, how should I explain that suddenly–”  
  
“Yes, I imagine the questions could get uncomfortable.” Sherlock was laughing at her. She took one step towards him, fingers itching for a gun.  
  
“He mustn’t know about me, Sherlock.”  
  
“He’s already  _dead_ , Mary. You killed him – didn’t you? I wonder. Why couldn’t we play this game? The game of John-getting-to-know.”  
  
“I can’t!” she cried. “I can’t lose him, Sherlock. I can’t have him rejecting me. I’d rather...” she trailed off, suddenly aware of the paradox.  
  
“Yes, Mary.” Sherlock stretched out his palm and his little sword landed on it, its toothy smile still almost non-existent. He regarded it with interest. “Getting there,” he murmured to himself.  
  
“Yes,” he repeated aloud, “why couldn’t you let him on your secret? Even if he did reject you, if he told you to leave and never show up again, it would mean your assignment was over. You’d be free. No need to pretend being the loving wife...”  
  
She snapped: “I didn’t–” Even when she swallowed the rest of the sentence, it was already too late.  
  
The sword smiled delightedly, clicking its teeth in a poignant  _clink_. Sherlock sat up, his whole body on alert. “This is the Truth. You didn’t  _pretend_.  
  
“You became Magnussen’s tool, to further his ends. You dutifully met John, made him interested in you, and got him to marry you. And somewhere along the road... you fell in love with him. The trap you’ve set entrapped you as well.”  
  
His accusatory voice suddenly became gentler: “And what’s worse, you knew he didn’t love you back the way you did. Oh, he did love you well enough – but not enough to forgive you if you broke him. John Watson is not the kind of man to give his trust twice.” He paused, then added softly: “I believe that’s my fault, there.”  
  
She wanted to cover her ears but the truth, once uncovered, couldn’t be silenced.  
  
“But then, you found yourself with a child. And that sealed the deal. Now John definitely wasn’t allowed to ever find out about you. You couldn’t bear the thought of him hating you – and worse, you couldn’t bear the thought of him  _tolerating_  you for the sake of the child.”  
  
“What do  _you_  know about that? You’re not even human, you...” she hissed through the tears streaming down her face.  
  
“About loving someone who doesn’t want to love back?” Sherlock closed his eyes briefly. “Human emotions are the line of my work, mapping their extent and gauging their strength is my trade. But, sad as it is, I’m not above them myself.”  
  
He stood up and stepped closer to her, tracing one of the tears with his fingertip. “I understand, Mary. That’s how I can help.”  
  
Sherlock turned to the mirror. The demon there pulled on another mask: it looked now very much like Sherlock, only in negative: dark skin instead of pale, white locks instead of raven ones. The demon bared its teeth in silent snarl.  
  
“Self-reproach, unrequited love, desperation. Emotions strong enough for a demon to latch on them, to grow on them, to become a sentient part of your soul. But, you see, in one respect a demon is a creature just like any other: it wants to exist. It was born bound to you, and it needed you to live.  
  
“This one, in his sense of self-preservation, gave you a fantasy where you killed your husband. It was the easiest way out: you’d never have to hear John saying  _no_  to you, you’d vanquish the leverage Magnussen craved, you’d eradicate the very point of his blackmail.”  
  
“And then the demon did his best to block your mind from the realisation that in suppressing your love, in hiding under layers of secrets, you’ve, in fact, killed your own soul.”  
  
The sword breathed a single word: “ _Regret_.”  
  
Sherlock took her by arms and led her towards the mirror. “Look, Mary. Who was it that you killed?”  
  
She didn’t want to look, but, in the end, she didn’t have the strength to close her eyes. In the mirror, Moriarty’s face paled and slowly morphed into her own.  
  
“Your Form,” Sherlock said in the same moment as she sobbed: “It’s me.”  
  
The Sword of Exorcism let out an unearthly sound and sprung from its sheath.

**Notes for the Chapter:**

> There will be an Epilogue.


	4. Epilogue

The front door creaked open – the hinges really could use some Vaseline – and then John’s voice echoed through the hallway, calling out:  
  
“Mary?”  
  
Sherlock didn’t move where he stood in the kitchen, staring out of the window, as he answered softly: “There’s no-one here.”  
  
“Mary?! Ma– oh.” John stopped dead in the kitchen door frame. “Sherlock? What are you doing here? Where’s my wife? Where’s my...” he drew in a deep breath, “...pregnant wife?”  
  
“She left.”  
  
John opened his mouth for another meaningless question and then the seriousness of Sherlock’s expression finally registered with him. He looked around, clenched his fist, driving the fingernails into his skin as if the pain could wake him from a bad dream, but the words weren’t coming. Sherlock waited.  
  
“How?” John managed to ask at last.  
  
 _I exorcised her demon and she decided never to give chance for another to grow within her. She left to keep you safe._  
  
There were things, Sherlock knew, John would never understand. So he settled for: “There’s a lot you didn’t know about your Mary, John. About who she was before.”  
  
John laughed, and it wasn’t a pleasant sound. “Well, you obviously know all about that! Then tell me! Tell me, Sherlock, and pray you have a good reason why you couldn’t tell me before!”  
  
Sherlock looked out of the window. “There wasn’t a reason to tell you. She was an assassin, ex-CIA and freelance since then, but she quit that life five years ago. She was the Mary you learned to love by the time she met you. She didn’t pose a threat to you.”  
  
John stumbled into the kitchen and slumped onto one chair, as if the weight of the world settled on his shoulders.  
  
“Then why is she gone? Was she afraid I would... reject her, once I found out?”  
  
“Would you forgive her?” Sherlock maintained his distance from John carefully, but the failed to hide the curiosity in his voice.  
  
John rested his head on his forearms. He spoke more to the table surface than to Sherlock when he sighed: “I... I suppose I would. She was carrying my child, for God’s sake.”  
  
“That’s what she thought,” Sherlock murmured to himself. John didn’t seem to hear that. After a long moment, Sherlock looked back and found John ostentatively waiting for the rest of the story.  
  
“When I was... abroad,” they averted each other’s eyes at the word, “she was blackmailed by a man named Charles Augustus Magnussen into becoming your friend, eventually your lover. Magnussen keeps profiles on almost every important person. He knew your type and what kind of personality you’d be most likely to fall for. He wanted her to become your pressure point, which in extension would give him considerable power over me.”  
  
John gasped. “You’re telling me... that my marriage...”  
  
“It’s not the end of the story, John,” Sherlock barked out, focused on not getting side-tracked. “Mary obeyed out of fear for her life, and set the trap on you, but in the end, she made one mistake. She fell in love.”  
  
John was very quiet for a long while, and when he finally spoke, it sounded like he wanted to laugh but the joke was simply too poor.  
  
“Mistake. Of course. Sentiment...”  
  
“Chemical defect, found on the losing side,” Sherlock quoted. “And the best nutrient substance for demons,” he added, as an afterthought.  
  
John looked around, trying to imagine a woman sitting at the kitchen table, tearing herself to shreds with the despair over loving the man she’s supposed to destroy, looking towards the day she’d have to betray the man she loves.  
  
“She left to go undercover once more. She’s probably after Magnussen, or trying for a deal with CIA once again, or simply eliminating her enemies so she could come back to you, this time with nothing breathing down her neck.  
  
“It’s probably a suicide mission. Her enemies are too many, and she’s pregnant. I’m sorry, John.” Sherlock really sounded sorry, and that somehow was the worst part.  
  
“So that’s it? Why do you – why do people always have to  _leave_  me behind without me having a bloody  _word_  in–”  
  
“She loves you, John.” The words rang through the kitchen, dragging the echo of their unspoken siblings behind them. John met Sherlock’s eyes and wished he didn’t see the defeat in them.  
  
“What do I do, Sherlock?”  
  
Sherlock shrugged. “She’s out of my reach, now. But we could go after Magnussen, together.” His voice held a promise of vengeance.  
  
“If there’s a way to bring him down, I’ll find it.”

**Notes for the Chapter:**

> As you probably noticed, this fic is my version of so-called "fix-it" fic, or, as I like to call it, "Mary's redemption" fic. I am going to pretend that His Last Vow actually went like this and not the stupid way it did.


End file.
